Perception of Cyclists by Motorists

To avoid an accident between a cyclist and a motorist the motorist must first notice the cyclist. What makes cyclists get noticed by motorists? Provided the driver is looking at the road ahead then surely the cyclist will be noticed? Not necessarily! BeSeenOnABike claim that drivers can suffer from two types of blindness: Inattentional Blindness and Change Blindness.

Why is fluorescent clothing recommened when riding a bicycle during the day? Why not wear bright clothes (white or yellow). Why wear bright clothes at all - whats wrong with black clothes whilst cycling?

The strange phenomenum of Inattentional Blindness suggests that we may not see something at all unless we are paying attention to it. (Blackmore, 2005). Psychologists Arien Mack & Irvin Rock held subjects attention by asking them to watch a fixation spot and, when a cross briefly appeared, to decide whether the vertical arm was longer than the horizontal arm. When a highly visible object unexpectantly flashed close to the cross, most subjects failed to see it. Even more surprising was that when they had to attend to a cross slightly to one side of where they were looking, they failed to see the object flashed right in front of their eyes. It seems that paying attention to one side makes you blind where you are looking. Mack and Rock conclude that there can be no conscious perception without attention.

In these studies, observers monitored one event while simultaneosly ignoring another similar event. Observers monitored one team of players passing a basketball while ignoring another team also passing a ball. The observers were asked to count the number of times that the team that was being monitored passed the ball. An Unexpected Event occurred. For example, a woman carrying an open umbrella might walk across the court. As in Mack & Rock's studies, observers often failed to see the Unexpected Event.

View the movie.

These studies demonstrate that attention is directed to objects and events rather than spatial locations - the attended event was literally superimposed on the unattended event, yet observers still did not see the Unexpected Event.

BeSeenOnABike claim that in some accidents involving cyclists being hit by motorists, the cyclist is the Unexpected Event. Because the motorist suffers from Inattentional Blindness the motorist never sees the cyclist! A cyclist wearing normal dark clothes may be not be visible to a motorist (the cyclist is an Unexpected Event). By wearing bright fluorescent clothing or other fluorescent gadgets rather than dark clothes, the motorist attends to the cyclist - and sees him! Maybe a fluorescent smiley could actually save lives!

What's the Difference between Looking and Seeing?

A large fraction of traffic accidents are of the type "driver looked but failed to see". Here, drivers collide with pedestrians or cyclists in plain view, with cars directly in front of them (the classic "rear-ender"), and even run into trains. That's right - run into trains, not the other way around!

In such cases, information from the world is entering the driver's eyes. But at some point along the way this information is lost, causing the driver to lose connection with reality. They are looking but they are not seeing.

What's going on? Our findings indicate that the critical factor is attention: To see an object change, it is necessary to attend to it.

To show this, Ronald Rensink developed a flicker paradigm in which an original and a modified image continually alternate, one after the other, with a brief blank field between the two. The onset of each blank field swamps the local motion signals caused by a change, short-circuiting the automatic system that normally draws attention to its location. Without automatic control, attention is controlled entirely by slower, higher-level mechanisms which search the scene, object by object, until attention lands upon the object that is changing. The change blindness induced under these conditions is a form of invisibility: it can become very difficult to see a change that is obvious once attended.

To see this effect for yourself, try out the following Change Blindness examples.

BeSeenOnABike claim that in some accidents involving cyclists being hit by motorists, the motorist suffers from Change Blindness. The motorist never sees the cyclist! Maybe a cyclist wearing a fluorescent jacket could actually saving their life by making the motorist attend to the jacket and thus see the cyclist!

References

• Inattentional Blindness (page 62) in Consciousness: A Very Short Introduction by Susan Blackmore, Pub: Oxford Uni. Press, 2005
• Inattentional Blindness An Overview By Arien Mack & Irvin Rock
• Overview of Inattentional Blindness (Visual Cognition lab)
• Visual Cognition Lab demos
• Monitor on Psychology